The present invention concerns a sealing tubular element, particularly suited to be applied to the poles of electric accumulators. It is a known fact that the inner elements of electric accumulators are connected to at least one pair of poles, one of them being positive and the other one negative, protruding from the lid of the container wherein said elements are contained, to which the electric conductors supplying power to corresponding engine are connected.
It is also a known fact that said poles consist of bodies having an essentially cylindrical shape which are provided with connecting means, suited to connect each pole to its respective cable supplying the corresponding engine, and with sealing mechanisms, co-operating with each pole and with the lid of the container wherein the elements are contained, suited to prevent the leaking out of electrolyte.
In particular, according to the known embodiments, the upper part of the pole is arranged passing through the corresponding hole drilled in the lid to which it is secured by means of a sealing ring-nut which can be threaded on the pole or on the lid, if the pole or the lid are threaded, or it can be cylindrical and inserted by pressure, if the pole or the lid are not threaded. Once said ring-nuts have been mounted, they produce the compression of the gaskets with which the pole is provided, thus realizing the seal for the electrolyte.
Ring-nuts inserted by pressure are usually preferred to threaded ring-nuts, since they make it unnecessary to have to realize threaded poles and seats of lids which are more costly and also because said ring-nuts can sometimes act as sealing gaskets for the electrolyte, if they are made of rubber.
The described sealing ring-nuts belonging to the known type present, however, the inconvenience in that they are mounted with interference on their respective poles and during the assembly they discharge on the inner elements of the accumulator all the stresses which are exerted on them because of the coupling process. These stresses can mechanically deform the elements of the accumulator, thus damaging them.